After update window 10, my laptop gets stuck in welcome screen

I updated my Dell Inspiron 15r to Window 10, everything seems ok until restart. After input my password, the screen get stuck in the welcome screen forever. I turned off wi-fi and restart, still the same. Now My computer is useless. Any suggestion to fix this?

That happened to me, or something similar, with my HP Pavilion dv6. You know that silly picture that covers the password screen -- you click on it and it "rises" out of the way? Well, mine kept going up and down, every time I tried to input my password, blocking the field. After a few hours of restarting I -- shh! I know it's shocking -- deliberately shut off the power while Windows was restarting, hoping to get the Windows rescue screen. But all that happened was a screen that came up with two buttons: one was "restart" and the other was "advanced options", which when clicked did absolutely nothing. I couldn't get to the Startup options menu by hitting "escape", even during the two seconds Windows offered that option. When I hit "escape" it simply ignored it.

I don't know if this is any comfort, but after another couple hours, the computer healed itself. I think it also helped that I plugged in a mouse, rather than using the one installed in the laptop. The computer seemed to ignore the latter, but responded almost instantly to the former. Good luck!